The invention relates to a boiling-water reactor comprising a reactor pressure vessel which encloses the reactor core and contains a steam space containing water separators, above the reactor core, and having control rods arranged so they can be adjusted within the reactor core by a drive located outside of the reactor pressure vessel.
In prior art boiling-water reactors, the control rods have been run into the pressure vessel by special drives positioned below the vessel with the control rods requiring to be lifted against the force of gravity. These control rods position neutron-absorbing elements within the core to control its fission. Such drives which must move the control rods against the force of gravity, must be very reliable and quick-acting because of the possibility that it may be necessary to scram the reactor. This makes such drives undesirably expensive.
The object of the present invention is to provide a better solution for the control of the core of a boiling-water reactor.